JP2010221280A - Press machine device and motor control device therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a press machine device including a crank mechanism and a motor control device for the press machine which are capable of, even when small foreign bodies generating disturbances having smaller amplitudes than that of the steady disturbance caused due to change in the moment of inertia of crank mechanism are caught in, reliably detecting those foreign bodies without arranging any sensor or the like dedicated for detecting the intrusion of foreign bodies, as well as realizing reduction in the price and the size of the press machine and increasing reliability thereof. <P>SOLUTION: The control device includes a disturbance observer unit 2 for calculating an estimated disturbance value with respect to a motor 1 based on a torque command and a motor velocity, and intrusion detection sections 3, 4, 5 for detecting the intrusion state of foreign matter between a press shaft and a cushion shaft based on the estimated disturbance value. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

TECHNICAL FIELD The present invention relates to a press machine device that forms a metal plate (non-molded product) with a mold and a motor control device thereof, and in particular, sandwiches foreign matter (for example, when a foreign matter is sandwiched or a minute object to be molded). The present invention relates to a press machine device and a motor control device for the press machine device that detect a case in which a waste of an object is sandwiched without arranging dedicated sensors.

The first conventional technique is “in a press apparatus that clamps a work material on a die with a stripper and presses the clamped work material by a press operation of an upper mold part and a lower mold part. "It is related to a detection device that detects foreign matter by relative movement of the part", and "detects the electrical continuity of the detection device and accurately detects foreign matter existing between the stripper and the work material or die." Then, there is a device that aims to provide a press apparatus capable of stopping the press operation at the same time as detecting a foreign object (for example, Patent Document 1).
FIG. 8 is a schematic configuration diagram showing a press device provided with the foreign object detection device in the first prior art. In addition, the code | symbol attached | subjected to drawing is described using the code | symbol described in 1st prior art.

In FIG. 8, “the pressing device 1 that clamps the workpiece W on the die 20 with the stripper 3 and presses the clamped workpiece W by the pressing operation of the upper die portion 2 and the lower die portion 4 is described above. The detection device 30 provided in the upper mold part 2 and the stripper 3 are provided in the stripper 3, and the stripper 3 is caused by the foreign matter M existing between the stripper 3 and the die 20 or the work material W to be in the upper mold part 2. And a contacted portion 32 that comes into contact with the detection device 30 and causes electrical conduction when moved relative to the detector.

The second prior art is “related to a foreign matter detection method and a safety device in a die room of a press machine”, and “a foreign matter detection method in a die room of a press machine having a die room in which a mold is installed. A step of detecting and storing a standby pattern of the shape pattern near the mold by the pattern detection means during standby of the machine; a step of detecting the startup pattern of the shape pattern near the mold by the pattern detection means when starting the press machine; A step of comparing the detected startup pattern with the stored standby pattern, a step of determining an abnormality when the two patterns compared do not match, a step of stopping the slide when determining that there is an abnormality, And a step of notifying the abnormality by the abnormality notifying means when it is determined to be abnormal ”(for example, Patent Document 2).
FIG. 9 is a schematic configuration diagram showing a press machine device provided with a safety device related to foreign object detection in the second prior art. In addition, the code | symbol attached | subjected to drawing is described using the code | symbol described in 2nd prior art.

In FIG. 9, “the output shaft of the electric motor 8 that is the drive source of the press machine 1 is connected to the flywheel 10 that smoothes the operation of the press machine 1 via the speed reducer 9. Is connected to the first gear 12 via the clutch & brake 11. When the output rotation of the flywheel 10 is transmitted to the first gear 12, the clutch of the clutch & brake 11 is engaged to Also, when stopping the rotation of the first gear 12, the clutch of the clutch & brake 11 is disengaged and the brake is applied.The first gear 12 has a second gear with more teeth than the first gear 12. 13 is engaged, and an output shaft of the second gear 13 is provided with a crank mechanism 14. The crank mechanism 1 for converting the rotational movement of the second gear 13 into a sliding movement. A slide 4 that moves up and down is attached to the output portion of the bolster 2, and an upper die 5 is attached to the lower surface of the slide 4. On the other hand, a lower die 3 is attached to the upper surface of the bolster 2. It is attached at a position opposite to 5. "

The third prior art is “Thorough prevention of accidents in the transfer device of the press”, “Transfer that controls the position of the beam moving three-dimensionally by a servo control device independent of the drive mechanism of the transfer press. In the device, the torque value measured in normal operation for each specific transfer pattern is set as the standard torque value of the pattern, and the upper limit torque value and the lower limit torque value obtained by adding or subtracting a preset deviation value to the standard torque value are allowed. A torque range is calculated and stored in the control device, and an actual torque value measured every time the specific transfer pattern is actually operated is compared with an allowable torque range and detected at the moment when the range deviates from the range. The position of a conventional beam or the like is detected by an abnormality detection device that monitors the torque of the transfer device. Dropping of unspecified members which can not be prevented by control only, pinching, lubrication failure, abnormal momentarily detect such a servo motor idling "there is. (For example, Patent Document 3)
FIG. 10 is a schematic configuration diagram showing a press transfer device provided with an abnormality detection device according to the third prior art. In addition, the code | symbol attached | subjected to drawing is described using the code | symbol described in 3rd prior art.

In FIG. 10, “specification is specified in the transfer device that drives the servo motors 11 and 21 in the driving devices 1 and 2 to positionally control the movement of the beam via the servo control devices 12 and 22 and synchronizes with the operation of the press body. The actual torque value T measured during normal operation for each transfer pattern is used as a standard, and the allowable torque range is calculated and stored based on the upper and lower torque values obtained by adding or subtracting a preset deviation value in the CPU 32 of the control device 3. In the same transfer pattern forming operation, information processing is incorporated in which whether or not the actual torque value is included in the stored allowable torque range and immediately deviates from the deviated region is incorporated.

As described above, the foreign matter detection of the press machine in the prior art is detected based on the output value of the arranged external detection device (Patent Document 1), or the torque from the servo motor without the external detection device. Some are detected based on a value or a change in shape near the mold (Patent Documents 2 and 3).
In addition, the method of detecting foreign object pinching without having an external detection device can also detect foreign object pinching by detecting the foreign object pinching as a disturbance to the servo motor and detecting or estimating the disturbance.

The fourth conventional technique includes a disturbance estimation observer, and detects a disturbance when the magnitude of the disturbance estimated thereby becomes a predetermined value or more (see, for example, Patent Document 4). .
Further, the fifth prior art also detects the disturbance when the estimated amount of change in the disturbance exceeds a predetermined set value by using the fourth conventional technique together (for example, (See Patent Document 5).

FIG. 11 is a schematic block diagram showing the flow of disturbance detection processing in the fourth conventional technique.
In the figure, reference numeral 111 denotes a motor, which inputs a torque command value output from a servo amplifier (not shown) to the motor 111 and the rotational speed of the motor 111 to the disturbance observer 112. The disturbance observer 112 calculates a disturbance estimated value from the torque command value and the motor speed, and outputs it to the comparator 113. The comparator 113 compares a predetermined set value with the estimated disturbance value, and detects the disturbance if the estimated disturbance value exceeds the set value.

FIG. 12 is a schematic block diagram showing the flow of disturbance detection processing in the fifth prior art.
In the figure, reference numeral 211 denotes a motor, which inputs a torque command value output from a servo amplifier (not shown) to the motor 211 and the rotational speed of the motor 211 to the disturbance observer 212. The disturbance observer 212 calculates a disturbance estimated value from the torque command value and the motor speed, and outputs it to the comparator 214 and the differentiator 215. The differentiator 115 performs time differentiation on the estimated disturbance value and outputs it to the comparator 216 as the rate of change of the estimated disturbance value. The comparator 214 compares a predetermined set value with the estimated disturbance value, and detects the disturbance if the estimated disturbance value exceeds the set value (disturbance detection 1). Comparator 216 compares a preset set value different from that of comparator 214 with the output value of differentiator 215 (rate of change in disturbance estimated value), and outputs the value of differentiator 215 (change in estimated disturbance value). Is detected as a disturbance (disturbance detection 2). When disturbance detection 1 or disturbance detection 2 is established, it is detected as a disturbance.

As described above, the disturbance detection method according to the related art includes a disturbance estimation observer, and the estimated disturbance estimated value exceeds a predetermined set value or an instantaneous change in the estimated disturbance estimated value. A disturbance was detected when (the rate of change of the estimated disturbance value) exceeded a predetermined set value.

JP 2007-054844 A (page 3-5, FIG. 1) JP 2001-259899 A (page 3-6, FIG. 2) JP-A-7-275971 (page 4, FIG. 1) Japanese Patent Laid-Open No. 03-196313 (page 2-4, FIG. 1) JP-A-11-254380 (page 3-5, FIG. 4)

In the press machine device in the prior art, there is an increasing demand for detecting a foreign object pinching without providing the proximity sensor as in the first prior art, and the servo motors in the second and third prior arts. By detecting the pinching of foreign matter based on the change in torque value from the sensor or by changing the shape pattern in the vicinity of the mold, it is possible to reduce the cost of the apparatus by not providing sensors such as proximity sensors, There are known techniques that can save the trouble of adjusting the sensors.

However, in the second prior art, since the pinching of the foreign matter is detected by the change in the shape pattern in the vicinity of the mold during standby and startup, the change in the shape pattern in the vicinity of the mold when a minute foreign matter is pinched. On the other hand, there is a problem that pinching detection with high detection accuracy cannot be achieved. Even in the third prior art, since the change in torque value from the servo motor is simply compared, there is a problem that a large torque value cannot be obtained when a minute foreign object is inserted.

Here, the press machine device described above is generally composed of an upper die portion and a lower die portion driven by a servo motor, and the servo motor is a crank mechanism via a mechanical mechanism using a plurality of gears. Is driven to reciprocate the upper mold part. The lower mold part is held by a position command by a servo motor via a rack and pinion.
In such a press machine apparatus, for example, the thickness and size may be different, and foreign objects may be pinched. However, these pinchings may greatly change the disturbance from the servo motor and determine the set value. There is a problem that it is difficult. In addition, there is a case where a minute foreign matter is sandwiched, but the sandwiching cannot be a great disturbance to the servo motor. Furthermore, even when no pinching has occurred (in the normal state), reaction force or the like due to change of moment of inertia by a crank mechanism that changes rotational motion to reciprocating motion is always detected as disturbance. . The reaction force caused by the change in the moment of inertia due to the crank mechanism that changes this rotational motion into reciprocating motion can be a greater disturbance than the reaction force caused by the foreign object pinching described above. I can't.

In the fourth or fifth prior art disturbance detection method, a disturbance estimation observer is provided, and the estimated disturbance estimate exceeds a predetermined set value or the estimated disturbance estimated value is instantaneous. When the change (the rate of change in the estimated disturbance value) exceeds a predetermined set value, it is detected as a disturbance, that is, since the predetermined set value is simply compared with the estimated disturbance value, Only foreign objects with larger disturbances than the disturbances that occur (reaction force caused by the change in the moment of inertia by the crank mechanism that changes the rotary motion described above) can be detected, and the estimated disturbance value depends on the thickness of the foreign object. There was a problem that it was difficult to determine the set value because it changed greatly.
The third prior art also has the same problem as the fourth or fifth prior art because it simply compares changes in the torque value from the servo motor.

Therefore, in the third to fifth prior arts, in order to detect the pinching of minute foreign matters in the press (in the case of the fine foreign matter having a thickness of less than 5 mm described above), no pinching has occurred ( When there is a disturbance (in the normal state) (a reaction force due to a change in the moment of inertia by the crank mechanism that changes the rotary motion described above to reciprocating motion), the reference value is made smaller than this disturbance (steady disturbance). It is necessary to set, and pinching cannot be detected. Also, in order to detect the pinching of various foreign objects in the press machine (in the case of foreign substances having different thicknesses and sizes as described above, etc.), the reference value is set by changing the thickness and size of the foreign objects to be inserted. It is difficult to detect pinching. In such cases, it is necessary to dispose a sensor or the like that is an external detection device as in the first prior art, and it is not possible to reduce the cost of the device, the labor of adjusting the sensors, and the like. There was also a problem.

The present invention has been made in view of the above problems, and is a press shaft (an upper die crank mechanism, a mechanical mechanism, a servo motor as a press shaft, a lower die rack and pinion, a servo in a press machine apparatus. Even if there is a steady disturbance on the motor (cushion shaft) or when foreign objects with different thicknesses and sizes are inserted, the sensors are not installed for detecting foreign object pinching. Reliable detection of foreign matter having a disturbance smaller than the disturbance (in the case of the above-mentioned minute foreign matter having a thickness of less than 5 mm) and various foreign matters (in the case of the above-mentioned foreign matters having different thicknesses and sizes). An object of the present invention is to provide a press machine device and a motor control device for the press machine device that can reduce the cost and size of the device and improve the reliability.

In order to solve the above problem, the present invention is configured as follows.
The invention according to claim 1 is a press machine device having a press shaft and a cushion shaft for processing a workpiece, and a motor that rotationally drives an upper mold portion of the press shaft via a mechanical mechanism; And a controller for supplying electric power to the motor, wherein the control device calculates a disturbance estimated value for the motor based on a torque command and a motor speed, and the disturbance estimation. And a pinching detector that detects a foreign object pinching state between the press shaft and the cushion shaft based on the value.
According to a second aspect of the present invention, the entrapment detection unit according to the first aspect of the present invention includes: an absolute value calculation unit that inputs the disturbance estimated value and calculates an absolute value of the disturbance estimated value; While the upper mold part moves within a predetermined range within the movable range of the mold part, an integrator that integrates the absolute value of the estimated disturbance value, and a setting value that is determined in advance by inputting the output of the integrator A comparison unit that compares and determines the foreign object pinching state, and the comparison unit determines that the foreign object pinching state is present when the output of the integrator exceeds the set value. To do.
According to a third aspect of the present invention, the pinch detection unit according to the first aspect of the invention inputs the disturbance estimated value and calculates an absolute value of the disturbance estimated value, and the disturbance. A position coefficient processing unit that inputs an absolute value of an estimated value and weights the estimated disturbance value with respect to the position of the upper mold part, and the upper mold part moves within a predetermined range within the movable range of the upper mold part Between the integrator that integrates the output of the position coefficient processing unit, and a comparator that inputs the output of the integrator and compares it with a predetermined set value to determine the foreign object pinching state, The comparison unit determines that the foreign object is caught when the output of the integrator exceeds the set value.
According to a fourth aspect of the present invention, the position coefficient processing unit according to the third aspect of the present invention has a coefficient of 1 when the upper die portion is at the bottom dead center position, and the upper die portion is at the bottom dead center position. A coefficient that becomes smaller than the coefficient 1 as the upper mold part moves away, and has a function in which the coefficient changes in accordance with the vertically movable position of the upper mold part, and the coefficient determined by the function and the absolute value of the estimated disturbance A value obtained by calculating a product with the value is output.
According to a fifth aspect of the present invention, the control device according to the first aspect of the invention outputs information indicating that the press machine is abnormal when detecting the foreign object pinching state. To do.
Further, in the invention described in claim 6, instead of the comparison unit in the invention described in claim 2 or 3, the output of the integrator is sampled every predetermined time, and the current sampling value and the previous sampling value A comparison unit that determines the occurrence of the foreign object pinching state based on the comparison.
A seventh aspect of the present invention is a press machine device having a press shaft and a cushion shaft for pressing a workpiece, and a motor that rotationally drives an upper mold portion of the press machine device through a mechanical mechanism. And a control device for supplying electric power to the motor, wherein the control device is a press machine in which a steady disturbance exists that is a vibration disturbance caused by a change in the moment of inertia of the mechanical mechanism. An abnormal disturbance is detected by detecting an abnormal disturbance and the steady disturbance, which are foreign matter sandwiched between a shaft and the cushion shaft.
According to an eighth aspect of the invention, the control device according to the seventh aspect of the invention provides a disturbance observer unit that calculates a disturbance estimated value for the motor based on a torque command and a motor speed, and the disturbance estimation. An absolute value calculation unit that inputs a value and calculates an absolute value of the estimated disturbance value, and an absolute value of the estimated disturbance value while the upper mold unit moves within a predetermined range within the movable range of the upper mold unit And a comparator that inputs the output of the integrator and compares it with a predetermined set value, and determines that the abnormal disturbance occurs when the output of the integrator exceeds the set value. These are provided.
According to a ninth aspect of the present invention, the control device according to the seventh aspect of the invention includes a disturbance observer unit that calculates a disturbance estimated value for the motor based on a torque command and a motor speed, and the disturbance estimation. An absolute value calculation unit that inputs a value and calculates an absolute value of the estimated disturbance value, and a position coefficient process that inputs the absolute value of the estimated disturbance value and weights the estimated disturbance value with respect to the position of the upper mold part , An integrator for accumulating the output of the position coefficient processing unit while the upper mold part moves within a predetermined range within the movable range of the upper mold part, and an input of the integrator to be input in advance A comparator that compares with the set value and determines that the abnormal disturbance occurs when the output of the integrator exceeds the set value.
According to a tenth aspect of the present invention, in the invention according to the ninth aspect, the position coefficient processing unit has a coefficient 1 when the upper die portion is at the bottom dead center position, and the upper die portion is at the bottom dead center position. A coefficient that becomes smaller than the coefficient 1 as the upper mold part moves away, and has a function in which the coefficient changes in accordance with the vertically movable position of the upper mold part, and the coefficient determined by the function and the absolute value of the estimated disturbance The invention according to claim 11 is characterized in that the control device in the invention according to claim 7 detects the foreign object pinching state. The press machine device outputs information indicating abnormality to the outside.
Further, in the invention described in claim 12, in place of the comparison section in the invention described in claim 8 or 9, the output of the integrator is sampled every predetermined time, and the current sampling value and the previous sampling value A comparison unit that determines the occurrence of the foreign object pinching state based on the comparison.
The invention according to claim 13 is a motor coupled to a mechanical mechanism, a detector that detects and outputs position or speed information of the motor, a host device that outputs a command, the command and the detector A control device that calculates a torque command based on the output of the motor and supplies electric power to the motor, wherein the host device or the control device is based on the torque command and the output of the detector. A disturbance observer unit for calculating a disturbance estimated value for the motor, an absolute value calculating unit for inputting the disturbance estimated value and calculating an absolute value of the disturbance estimated value, and an absolute value of the disturbance estimated value for a predetermined time. An integrator that integrates the output for a period of time, and a comparison unit that inputs the output of the integrator and compares it with a predetermined set value, and determines that an abnormal disturbance has occurred when the output of the integrator exceeds the set value; With It is characterized in.
The invention according to claim 14 is a motor coupled to a mechanical mechanism, a detector that detects and outputs position or speed information of the motor, a host device that outputs a command, the command and the detector A control device that calculates a torque command based on the output of the motor and supplies electric power to the motor, wherein the host device or the control device is based on the torque command and the output of the detector. A disturbance observer unit for calculating a disturbance estimated value for the motor, an absolute value calculating unit for inputting the disturbance estimated value to calculate an absolute value of the disturbance estimated value, and the disturbance estimated value for the position information of the detector A position coefficient processing unit that performs weighting, an integrator that integrates the output of the position coefficient processing unit for a predetermined time, and the output of the integrator is input and compared with a predetermined set value. If the output of the integrator exceeds the set value, it is characterized in that and a comparing section for determining the occurrence of abnormal disturbance.
Further, the invention according to claim 15 outputs information indicating that the motor control device is abnormal when the host device or the control device according to claim 13 or 14 detects the abnormal disturbance to the outside. It is characterized by doing.
Further, in the invention described in claim 16, in place of the comparison unit in the invention described in claim 13 or 14, the output of the integrator is sampled every predetermined time, and the current sampling value and the previous sampling value are And a comparison unit that determines the occurrence of the abnormal disturbance based on the comparison.

According to the first, second, seventh, and eighth aspects of the present invention, there is a steady disturbance (such as a reaction force due to a change in the moment of inertia caused by the crank mechanism that changes the rotary motion into the reciprocating motion) on the press shaft in the press machine. Even in the case, it is more than the steady disturbance caused by foreign object pinching (such as when a foreign object is pinched or when a small piece of molded object is pinched) without providing dedicated sensors for detecting foreign object pinching. A small-amplitude disturbance or a disturbance with a short vibration period can be reliably detected, and the apparatus can be reduced in price, size, and reliability.
In addition, according to the inventions of claims 3, 4, 9, and 10, in addition to the effects of the inventions of claims 1, 2, 7, and 8, it is possible to determine in advance the set value in the final stage comparator. It is easy to perform, and more accurate and reliable detection can be performed.
Further, according to the inventions of the fifth and eleventh aspects, it is possible to immediately stop the press machine device to inform the worker etc. of the foreign object biting state between the press shaft and the cushion shaft. After removing the foreign object biting state, the press machine can be safely operated again.
Further, according to the inventions described in claims 6 and 12, an abnormality can be easily determined. According to the thirteenth aspect of the present invention, even when a steady disturbance (such as a reaction force due to a change in the moment of inertia caused by a crank mechanism that changes the rotational motion to a reciprocating motion) exists on the press shaft in the press machine, foreign matter is caught Disturbances or vibrations with a smaller amplitude than steady disturbances due to foreign object pinching (such as when a foreign object is pinched or a small piece of molded object is pinched) without the dedicated sensors for detection. It is possible to reliably detect a disturbance accompanied by a change with a short cycle, and to reduce the cost and size of the apparatus and improve the reliability.
According to the invention described in claim 14, in addition to the effect of the invention described in claim 13, it becomes easier to predetermine the set value in the comparator at the final stage, and more accurate and reliable detection. Can do.
According to the invention described in claim 15, the motor control device can be stopped immediately to notify the worker etc. of the foreign object biting state between the press shaft and the cushion shaft. After removing the congested state, the motor control device can be safely operated again.
In addition, according to the invention described in claim 16, it is possible to easily determine an abnormality.

Schematic configuration diagram of a press machine apparatus according to an embodiment of the present invention. Schematic block diagram showing the flow of disturbance detection processing of the press machine according to the present invention Disturbance estimation waveform diagram at the time of unpinching in the press machine according to the present invention Disturbance estimation waveform diagram during pinching in the press machine according to the present invention Integral waveform diagram of disturbance estimated value at the time of pinching in the press machine according to the present invention The schematic block diagram which shows the flow of the process of the disturbance detection of the other form of the press machine apparatus which concerns on this invention Integral waveform diagram of disturbance estimated value at the time of pinching of another form in the press machine device according to the present invention Schematic configuration diagram showing a foreign object pinching detection device in the first prior art The schematic block diagram provided with the foreign material detection method in the die room of the press machine apparatus in 2nd prior art Schematic configuration diagram of press transfer device in third prior art Schematic block diagram showing the flow of disturbance detection processing in the fourth prior art Schematic block diagram showing the flow of disturbance detection processing in the fifth prior art

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic configuration diagram of a press according to an embodiment of the present invention. In the figure, 11 is a crank mechanism, 12 is a press shaft, 13 is an upper mold portion, 14 is a lower mold portion, 15 is a cushion shaft, and 16 is a rack and pinion. As described above, the upper mold portion 13 is provided with the crank mechanism 11 that is driven by a servo motor (not shown), and the servo motor (not shown) is a mechanical mechanism using a plurality of gears (not shown). The upper die is driven based on a command from a control device (not shown) such as a servo amplifier.

The press shaft 12 uses the crank mechanism 11 and moves the upper mold portion 13 up and down at a constant speed by speed control. The cushion shaft 15 uses a rack and pinion 16 and holds the lower mold part 14 at a fixed position by position control. When the upper mold part 13 of the press shaft 12 is lowered and the lower mold part 14 is pressed and pressed, the upper mold part 13 and the lower mold part 14 are simultaneously lowered, and when the upper mold part 13 is raised, the lower mold part 14 is rack and pinion. 16 is used to ascend to the command position.

FIG. 2 is a schematic block diagram showing the flow of disturbance detection processing of the press machine according to the present invention. In the figure, 1 is a motor, 2 is a disturbance observer, 3 is an absolute value calculation unit, 4 is an integrator, and 5 is a comparator. The disturbance detected here is pinching in the above-mentioned press machine device (when the above-mentioned minute foreign matter is pinched or when a small piece of molding object is pinched), and this disturbance detection is performed by the press machine device. In a control device (not shown) such as a servo amplifier. Also, when detecting disturbance, the press machine according to the present invention is stopped, the operator is notified of foreign object pinching, and after the worker has removed the pinch, the press machine apparatus according to the present invention is restarted. To drive.

A torque command value output to the motor 1 from a control device (not shown) such as a servo amplifier and the rotational speed (motor speed) of the motor 1 are input to the disturbance observer 2. The disturbance observer 2 calculates a disturbance estimated value from the torque command value and the motor speed and outputs it to the absolute value calculation unit 3. The absolute value calculation unit 3 calculates the absolute value of the estimated disturbance value and outputs it to the integrator 4. The technical significance of the absolute value calculation unit 3 will be described later. The integrator 4 always accumulates the estimated disturbance value and outputs it to the comparator 5 while the crank mechanism 11 of the press shaft of the press machine device according to the present invention rotates by a predetermined rotation angle. The comparator 5 compares the preset set value with the output value of the integrator 4, and detects the disturbance if the output value of the integrator 4 exceeds the set value.

Here, the motor speed may be a position connected to the motor 1 or an output signal of a speed detector (not shown). The disturbance observer 2 that calculates and outputs the estimated disturbance value based on the torque command value and the motor speed may be a known disturbance observer. Still further, since one rotation of the crank mechanism of the press shaft of the press machine device is known in advance in specifications such as a gear ratio between a mechanical mechanism using a plurality of gears for driving the crank mechanism and a servo motor, this One press of the crank mechanism of the press shaft may be made based on the specification (when the servo motor directly drives the upper mold portion via the crank mechanism, one rotation of the servo motor becomes one rotation of the crank mechanism).
As described above, the difference between the present invention and the prior art is that a sensor dedicated for detecting foreign object pinching is not provided, and the estimated disturbance value is not merely compared with a predetermined set value, The absolute value of the estimated value is always integrated while the press shaft crank mechanism rotates by a predetermined rotation angle, and then the integrated value is compared with a predetermined set value, and pinching is determined based on the comparison result. It is to be.

FIG. 3 is a disturbance estimated waveform diagram at the time of non-pinching in the press machine according to the present invention. In the figure, the vertical axis represents the amplitude of the estimated disturbance value, and the horizontal axis represents the rotation angle (0 ° to 360 °) of the crank mechanism of the press shaft.
In the figure, the solid line is the estimated disturbance waveform, and the range shown in the almost entire part in the figure is a range corresponding to one rotation at the angle of the crank mechanism of the press shaft. Also, the two dot-dash line circles indicated in the left part and the right part in the figure are caused by changes in the moment of inertia due to the crank mechanism of the press shaft, for example, when the rotation angle of the crank mechanism is 90 °, 270 °, This is where the disturbance with the largest amplitude occurs.
As described above, in the press machine according to the present invention, there is a steady disturbance when no pinching occurs (in a normal state). Further, since the steady disturbance as shown in FIG. 3 may be positive or negative with reference to the amplitude zero of the estimated disturbance value, the absolute value calculation unit 3 calculates the absolute value of the estimated disturbance value to the integrator 4. Output and detect the inclusion of a foreign object as will be described later.
Here, when the servo motor directly drives the upper mold part via the crank mechanism, the crank mechanism has an angle of 0 ° or 360 ° at the top dead center of the upper mold part and 180 ° at the bottom dead center of the upper mold part. It is.

FIG. 4 is a disturbance estimated waveform diagram at the time of pinching in the press machine according to the present invention. In the figure, the vertical axis indicates the amplitude of the estimated disturbance value, and the horizontal axis indicates the angle (0 degree to 360 degrees) of the crank mechanism of the press shaft. Further, in the figure, the solid line is the disturbance estimation waveform, and the range shown in almost the whole part in the figure is a range corresponding to one rotation at the angle of the crank mechanism of the press shaft. FIG. 4 shows a situation in which the operation of the press machine device is the same as that in FIG. 3, and a minute foreign matter is intentionally placed on the lower mold part and is artificially pinched.
A dot-and-dash circle portion shown in the center portion in the figure is a portion where a disturbance caused by a pinching smaller than a steady disturbance (disturbance due to change in the inertia moment of the crank mechanism) shown in FIG. 3 occurs. In addition, a disturbance caused by foreign object pinching occurs mainly when the upper mold part is at the bottom dead center (the angle of the crank mechanism is 180 °).
Thus, the angle of the crank mechanism at which the disturbance due to foreign object pinching occurs is limited to a certain angle range with reference to 180 °, and in this embodiment, the crank mechanism rotates 110 ° to 250 °, This will be described as a predetermined angle of the crank mechanism in which a disturbance due to foreign object pinching occurs. Note that the predetermined angle may be appropriately determined as necessary.

FIG. 5 shows the result of integrating the absolute values of the estimated disturbance values at the time of pinching in the press shaft according to the present invention. In the figure, the vertical axis represents an integrated value of absolute values of disturbance estimated values for the crank mechanism 110 ° to 250 ° rotation of the upper mold part, and the horizontal axis represents the total number of sample points for the crank mechanism 110 ° to 250 ° rotation.
The black circles at the top of the figure indicate that when pinching occurs (for example, the state shown in FIG. 4), the crank mechanism of the press shaft is rotating 110 ° to 250 ° (disturbance due to pinching in FIG. 4 occurs. It is a value obtained by always integrating the estimated disturbance values in the interval of 110 ° to 250 °. Also, the black circles in the lower part of the figure indicate the case where the crank mechanism of the press shaft is rotating 110 ° to 250 ° when pinching does not occur, that is, when only steady disturbance occurs (for example, the state shown in FIG. 3). This is a value obtained by always integrating the estimated disturbance value. In addition, when pinching has occurred and when it has not occurred (that is, when only steady disturbance has occurred), since data is sampled every 3 ms, both of them are 7.75 s from 110 ° to 250 °, and 2600 samples. Accumulated.
In the press machine according to the present invention, when the crankshaft mechanism of the press shaft is rotated 110 ° to 250 °, the estimated disturbance value is always integrated as an absolute value, and only a steady disturbance occurs and pinching occurs. In this case, for example, a clear difference can be made such that it is separated by a one-dot chain line in the figure.
Therefore, if the level delimited by the alternate long and short dash line is set to a predetermined setting value in the comparator, the pinching can be detected only when the pinching occurs.

  FIG. 6 is a schematic block diagram showing a flow of disturbance detection processing of another embodiment of the press machine according to the present invention. In the figure, 1 is a motor, 6 is a disturbance observer, 7 is an absolute value calculation unit, 8 is a position coefficient processing unit, 9 is an integrator, and 10 is a comparator. The difference from the first embodiment (FIG. 2) is that a position coefficient processing unit 8 that inputs an absolute value of a disturbance estimated value that is an output of the absolute value calculation unit 7 and an integrator that integrates the output of the position coefficient processing unit. 9 are the same, and the configuration other than that is the same.

The position coefficient processing unit 8 calculates the product of the coefficient determined by a certain function and the absolute value of the estimated disturbance value, thereby weighting the estimated disturbance value with respect to the position of the upper mold part on the press shaft where pinching occurs. .
Here, a certain function is a factor of 1 when the upper mold part of the press shaft is pressed to the lower mold part (bottom dead center), and as the upper mold part of the press shaft moves away from the position of pressing to the lower mold part. The coefficient becomes smaller than the coefficient 1 (coefficient 0 when the upper die portion of the press shaft is at the top dead center). For example, “1- | position where the upper die portion of the press shaft is pressed into the lower die portion− This is represented by the current rotation position of the crank mechanism of the press shaft | (absolute value). If the current rotation position of the crank mechanism of the press shaft is close to the position where the upper die portion of the press shaft is pressed into the lower die portion, there is a high possibility that the press shaft will be pinched, so the disturbance estimation value is further weighted. On the other hand, if the current rotational position of the crank mechanism of the press shaft is far from the position where the upper die part of the press shaft is pressed into the lower die part, there is little risk of pinching the press shaft, so disturbance estimation The value weighting is lowered.
Thereby, it becomes easier to determine a set value in the comparator 10 described later in advance than the detection of the pinching state in the first embodiment, and high-accuracy and reliable detection can be performed. It should be noted that the position where the upper die portion of the press shaft is pressed into the lower die portion has specifications such as a gear ratio between a mechanical mechanism using a plurality of gears and a servo motor for driving the upper die portion of the press shaft. Since it is known in advance, it can be set or understood before the press machine is normally operated. Therefore, the processing in the position coefficient processing unit 8 described above can be performed without any problem.

The integrator 9 always accumulates and outputs the output value of the position coefficient processing unit 8 to the comparator 10 while the crank mechanism of the press shaft of the press machine device according to the present invention makes one rotation. The comparator 10 compares the preset set value with the output value of the integrator 9, and detects the disturbance if the output value of the integrator 9 exceeds the set value.

FIG. 7 is a result of integration of estimated disturbance values at the time of pinching in another form in the press machine according to the present invention. In the figure, the vertical axis represents an integrated value of disturbance estimated values for the press shaft crank mechanism 110 ° to 250 ° rotation, and the horizontal axis represents the total number of sample points for the press shaft crank mechanism 110 ° to 250 ° rotation.
The white circles in the lower part of the figure indicate disturbance estimation during rotation of the crank mechanism 110 ° to 250 ° when pinching has not occurred, that is, when only steady disturbance has occurred (for example, the state shown in FIG. 3). It is a value obtained by always integrating the output obtained by performing the position coefficient processing described in the second embodiment on the value. Also, the white circles at the top of the figure indicate that there is a disturbance caused by the pinching in FIG. 4 during the rotation of the crank mechanism 110 ° to 250 ° of the press shaft when pinching occurs (for example, the state shown in FIG. 4). This is a value obtained by always integrating the output obtained by performing the position coefficient processing in the second embodiment with respect to the estimated disturbance value in the range of 110 ° to 250 °. Like FIG. 3 and FIG. 4, since data is sampled every 3 ms in both FIG. 3 and FIG. 4, both are 7.75 s from 110 ° to 250 °, and 2600 samples are integrated.
Here, the black dots in the figure are the same as those shown in FIG. 5 of the first embodiment, and in order to make the further effects of the second embodiment remarkable when the first and second embodiments are compared. Plotting.
Therefore, in the case of the second embodiment, it is possible to make a further clear difference between the case where only the steady disturbance is generated and the case where the foreign object is caught as compared with the first embodiment, which is determined in advance in the comparator. The set value can be determined more easily, and foreign object pinching can be detected only when foreign object pinching occurs.
Comparing FIG. 5 and FIG. 7 described above, the difference between the time when the foreign object is caught and the time when the object is not caught is large, so that it is possible to easily determine the preset setting value.

Here, in the above-described first or second embodiment, it is described that the control device detects an abnormal disturbance (foreign object pinching state) by comparing the integrated value of the absolute value of the estimated disturbance value with a predetermined set value. However, it may be simply a sampling comparison of the integrated value of the absolute value of the estimated disturbance value. For example, the integrated value of the estimated disturbance value is sampled (stored) at each control cycle, and an abnormality is determined from the change between the integrated value of the estimated disturbance value sampled this time and the integrated value of the estimated disturbance value before or several times before the sampling. To do.

In the first or second embodiment described above, the control device “provides electric power to the motor” such as a servo amplifier (for example, the position, speed, torque, etc. received from the host device, such as position, speed, torque). However, it may have a configuration corresponding to the disturbance observer unit and the pinch detection unit described above. For example, even a host device such as a controller that generates a command can be configured.

Further, in the first or second embodiment described above, the weighting function of the estimated disturbance value with respect to the position of the upper mold part in the press shaft where the pinching in the position coefficient processing unit occurs, the upper mold part of the press shaft presses the lower mold part. In the case of the position (bottom dead center), the coefficient is 1, and the coefficient that becomes smaller than the coefficient 1 as the upper die portion of the press shaft moves away from the position where the lower die portion is pressed (the upper die portion of the press shaft is top dead). In the case of a point, the coefficient is 0), for example, represented by “1- | position where the upper die portion of the press shaft is pressed into the lower die portion—current position of the crank mechanism of the press shaft | (absolute value)” However, the present invention is not limited to this function, and it is needless to say that other functions may be used as long as they are functions that weight the disturbance estimated value with respect to the motor speed.

11 Crank mechanism 12 Press shaft 13 Upper mold part 14 Lower mold part 15 Cushion shaft 16 Rack & pinion 1 Motor 2, 6 Disturbance observer 3, 7 Absolute value calculation part 4, 9 Integrator 5, 10 Comparator 8 Position coefficient processing part

Claims (16)

A press machine device having a press shaft and a cushion shaft for processing a workpiece, a motor for rotationally driving an upper mold portion of the press shaft through a mechanical mechanism, and a control device for supplying electric power to the motor In a press machine device comprising:
A disturbance observer unit that calculates a disturbance estimated value for the motor based on a torque command and a motor speed;
A press machine apparatus, comprising: a pinching detection unit that detects a foreign object pinching state between the press shaft and the cushion shaft based on the estimated disturbance value. The pinching detection unit is configured to input the disturbance estimated value and calculate an absolute value of the disturbance estimated value;
An integrator that integrates the absolute value of the estimated disturbance value while the upper mold part moves within a predetermined range within the movable range of the upper mold part;
A comparator that inputs the output of the integrator and compares it with a predetermined set value to determine the foreign object pinching state; and
2. The press machine device according to claim 1, wherein when the output of the integrator exceeds the set value, the comparison unit determines that the foreign object is sandwiched. The pinching detection unit is configured to input the disturbance estimated value and calculate an absolute value of the disturbance estimated value;
A position coefficient processing unit that inputs the absolute value of the estimated disturbance value and weights the estimated disturbance value with respect to the position of the upper mold part; and
An integrator that integrates the output of the position coefficient processing unit while the upper mold unit moves within a predetermined range within the movable range of the upper mold unit;
A comparator that inputs the output of the integrator and compares it with a predetermined set value to determine the foreign object pinching state; and
2. The press machine device according to claim 1, wherein when the output of the integrator exceeds the set value, the comparison unit determines that the foreign object is sandwiched. When the position coefficient processing unit is at the bottom dead center position of the upper mold part, the coefficient is 1, and a coefficient that becomes smaller than coefficient 1 as the upper mold part moves away from the bottom dead center position of the upper mold part. Having a function in which the coefficient changes according to the vertically movable position of the part,
The press machine device according to claim 3, wherein a value obtained by calculating a product of a coefficient determined by the function and an absolute value of the estimated disturbance value is output. The press machine device according to claim 1, wherein the control device outputs information indicating that the press machine device is abnormal to the outside when the foreign object pinching state is detected. In place of the comparison unit, the comparator includes a comparison unit that samples the output of the integrator at predetermined time intervals and determines the occurrence of the foreign object pinching state based on a comparison between the current sampling value and the previous sampling value. The press machine according to claim 2 or 3, wherein A press machine device having a press shaft and a cushion shaft for pressing a workpiece, a motor for rotating and driving an upper mold part of the press machine device through a mechanical mechanism, and supplying electric power to the motor A press machine with a steady disturbance, which is a vibration disturbance caused by a change in the moment of inertia of the mechanical mechanism,
The control device discriminates between an abnormal disturbance and the steady disturbance, which is a foreign object sandwiched state between the press shaft and the cushion shaft,
A press machine apparatus that detects the abnormal disturbance. A disturbance observer unit for calculating a disturbance estimated value for the motor based on a torque command and a motor speed;
An absolute value calculation unit that inputs the estimated disturbance value and calculates an absolute value of the estimated disturbance value, and the estimated disturbance value while the upper mold part moves within a predetermined range within the movable range of the upper mold part. An integrator that accumulates absolute values of
A comparator that inputs the output of the integrator and compares it with a predetermined set value, and determines that it is the abnormal disturbance when the output of the integrator exceeds the set value. The press according to claim 7. A disturbance observer unit for calculating a disturbance estimated value for the motor based on a torque command and a motor speed;
An absolute value calculation unit that inputs the disturbance estimated value and calculates the absolute value of the disturbance estimated value;
A position coefficient processing unit that inputs the absolute value of the estimated disturbance value and weights the estimated disturbance value with respect to the position of the upper mold part; and
An integrator that integrates the output of the position coefficient processing unit while the upper mold unit moves within a predetermined range within the movable range of the upper mold unit;
A comparator that inputs the output of the integrator and compares it with a predetermined set value, and determines that it is the abnormal disturbance when the output of the integrator exceeds the set value. The press machine device according to claim 7. When the position coefficient processing unit is at the bottom dead center position of the upper mold part, the coefficient is 1, and a coefficient that becomes smaller than coefficient 1 as the upper mold part moves away from the bottom dead center position of the upper mold part. Having a function in which the coefficient changes according to the vertically movable position of the part,
The press machine device according to claim 9, wherein a value obtained by calculating a product of a coefficient determined by the function and an absolute value of the estimated disturbance value is output. 8. The press machine device according to claim 7, wherein the control device outputs information indicating that the press machine device is abnormal to the outside when detecting the foreign object pinching state. In place of the comparison unit, the comparator includes a comparison unit that samples the output of the integrator at predetermined time intervals and determines the occurrence of the foreign object pinching state based on a comparison between the current sampling value and the previous sampling value. The press machine according to claim 8 or 9, characterized in that. A torque command based on a motor connected to a mechanical mechanism, a detector that detects and outputs position or speed information of the motor, a host device that outputs a command, and the command and the output of the detector; In a motor control device comprising a control device that calculates and supplies power to the motor,
A disturbance observer unit for calculating a disturbance estimated value for the motor based on the torque command and the output of the detector;
An absolute value calculation unit that inputs the disturbance estimated value and calculates the absolute value of the disturbance estimated value;
An integrator for accumulating the absolute value of the estimated disturbance value for a predetermined time;
A comparator that inputs the output of the integrator and compares it with a predetermined set value, and determines that an abnormal disturbance has occurred when the output of the integrator exceeds the set value; Motor control device. A torque command based on a motor connected to a mechanical mechanism, a detector that detects and outputs position or speed information of the motor, a host device that outputs a command, and the command and the output of the detector; In a motor control device comprising a control device that calculates and supplies power to the motor,
A disturbance observer unit for calculating a disturbance estimated value for the motor based on the torque command and the output of the detector;
An absolute value calculation unit that inputs the disturbance estimated value and calculates the absolute value of the disturbance estimated value;
A position coefficient processing unit for weighting the disturbance estimated value with respect to the position information of the detector;
An integrator for integrating the output of the position coefficient processing unit for a predetermined time;
A comparator that inputs the output of the integrator and compares it with a predetermined set value, and determines that an abnormal disturbance has occurred when the output of the integrator exceeds the set value; Motor control device. The motor control device according to claim 13 or 14, wherein when the host device or the control device detects the abnormal disturbance, the motor control device outputs information indicating that the motor control device is abnormal. A comparator that samples the output of the integrator every predetermined time instead of the comparator and determines the occurrence of the abnormal disturbance based on a comparison between the current sampling value and the previous sampling value. 15. The motor control device according to claim 13 or 14, characterized in that:

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